DESCRIPTION
The 74VHC257 is an advanced high-speed CMOS QUAD 2 CHANNEL MULTIPLEXER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. It is composed of four independent 2 channel multiplexers with common SELECT and ENABLE INPUT. PIN CONNECTION AND IEC LOGIC SYMBOLS June 1999 1/9 74VHC257 INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No 1 2, 5, 14, 11 3, 6, 13, 10 4, 7, 12, 9 15 8 16 SYMBOL SELECT 1A to 4A 1B to 4B 1Y to 4Y OE GND VCC NAME AND FUNCT ION Common Data Select Input Data Input From Source A Data Inputs from Source B 3 State Multiplexer Outputs 3 State Output Enable Inputs (Active LOW) Ground (0V) Positive Supply Voltage TRUTH TABLE INPUT S OE H L L L L X = DON’T CARE Z = HIGH IMPEDANCE OUTPUTS A X L H X X B X X X L H Y Z L H L H SELE CT X L L H H LOGIC DIAGRAM Thislogic diagram has notbe used to estimate propagation delays 2/9 74VHC257 ABSOLUTE MAXIMUM RATINGS
Symbol VCC VI VO IIK IOK IO Tstg TL Supply Voltage DC Input Voltage DC...
STMicroelectronics
